Navigation Links
Plasmolysis


Plasmolysis is the contraction of cells within plants due to the loss of water through osmosis. It is the cell membrane peeling off of the cell wall and the vacuole collapsing. Plasmolysis occurs when a plant cell's membrane shrinks away from its cell wall. This phenomenon occurs when water is drawn out of the cell and into the extracellular (outside cell) fluid. The movement of water occurs across the membrane moving from an area of high water concentration to an area of lower water concentration outside the cell. It is unlikely to occur in nature, except in severe conditions. Plasmolysis is induced in the laboratory by immersing a plant cell in a strongly saline(salty) or sugary solution, so that water is lost by osmosis. If onion epidermal (outer) tissue is immersed in a solution of calcium nitrate, cells rapidly lose water by osmosis and the protoplasm of the cells shrinks. This occurs because the calcium and nitrate ions freely permeate the cell wall and encounter the selectively permeable plasma membrane. The large vacuole in the center of the cell originally contains a dilute solution with much lower osmotic pressure than that of the calcium nitrate solution on the other side of the membrane. The vacuole thus loses water and becomes smaller. The space between the cell membrane and the cell wall enlarges and the plasma membrane and the protoplasm within it contract to the center of the cell. Strands of cytoplasm extend to the cell wall because of plasma membrane-cell wall attachment points. If plasmolysed cells are not transferred quickly from the salt or sugar solution to water so their vacuole may be refilled, cytorrhysis will begin.

External links


'"/>


(Date:5/22/2013)... responsible for legionellosis, an infectious disease that can lead ... has developed a complex method enabling it to camouflage ... these acting against the infectious bacteria. , Research led ... which teams from the National Institute of Health (NIH) ... Barcelona (BSC) have also participated, has described for the ...
(Date:5/22/2013)... new details on how climate change will affect interactions ... the Journal of Animal Ecology . This knowledge, ... informing policymakers of how species are likely to be ... a growing recognition among biologists that climate change is ... this is going to have very important consequences for ...
(Date:5/22/2013)... May 22, 2013 Early screening for prostate cancer ... testing is for women, thanks to UC Irvine research ... Chemical Society . , After more than a decade ... to clearly identify clinically usable markers for prostate cancer ... far sooner, with greater accuracy and at dramatically lower ...
Breaking Biology News(10 mins):Mechanism discovered which aids Legionella to camouflage itself in the organism 2UCLA life scientists present new insights on climate change and species interactions 2UCLA life scientists present new insights on climate change and species interactions 3UCLA life scientists present new insights on climate change and species interactions 4UCLA life scientists present new insights on climate change and species interactions 5UCI chemists devise inexpensive, accurate way to detect prostate cancer 2UCI chemists devise inexpensive, accurate way to detect prostate cancer 3
... people prefer to wipe the venomous little varmints off the face ... yards. The reviled South American native that invaded the U.S. Sun ... Solenopsis invicta and everywhere else as a painful pest in the ... An ardent fire ant fan and one of its foremost researchers ...
... genes influence the development and use of neural circuits ... the fruit fly, researchers have provided new insight into ... prior experience ?arise in the developing nervous system. The ... of Stephen Goodwin's group at the University of Glasgow, ...
... discovery of a novel class of mutations that disrupt the ... The mutation created the appearance of an "illegitimate" microRNA (miRNA) ... in its normal form. In this study, the gene ... skeletal muscle and the function of the derived protein is ...
Cached Biology News:Fire ants: Their true story told by the scientist who loves them 2Fire ants: Their true story told by the scientist who loves them 3Fly's courtship sheds light on the formation of innate behaviors 2
Other biology definitionOther Tags